Why Should I Use This Rather Than The Built-In Hoptoad JavaScript Notifier?

Well, you don’t have to.
I decided to write my own javascript notifier since the standard hoptoad notifier feels very clumsy (7.75KB or 3.08KB gzipped) and is packed with features I don’t need.
However, if you need extended error information (including a proper stack trace etc.) you should rather use the hoptoad code.